.middle {
    width: 1000px;
    /*height: 500px;*/
    border: 1px solid red;
    margin: 50px auto;
    overflow: hidden;
}

.middle > div:nth-child(2) {
    padding: 10px;
}

.middle > div:nth-child(2) > div {
    text-indent: 3em;
    margin-bottom: 30px;
    line-height: 30px;
}

.middle > div:nth-child(3) {
    display: flex;
    justify-content: center;
    width: 300%;

    position:relative;
    animation: marginLeft linear 2s infinite normal;
    -webkit-animation: marginLeft linear 2s infinite normal;
}

@keyframes marginLeft {
    0% {
        margin-left: 0;
    }


    33.3% {
        margin-left: -600px;
    }

    62% {
        margin-left: -600px;
    }


    100% {
        margin-left: 0;
    }
}
@keyframes marginLeft {
    0% {
        margin-left: 0;
    }


    33.3% {
        margin-left: -600px;
    }

    62% {
        margin-left: -600px;
    }


    100% {
        margin-left: 0;
    }
}

.middle > div:nth-child(3) img {
    width: 200px;
    height: 200px;
    margin: 20px;
}